/* // preload sketchbook images
for (var i = 0; i < sketch.length; i++) {
	temp_img = newImage(sketch[i]);
}*/

// preload arrow images
next_over = newImage("images/arrows/next-over.gif");
prev_over = newImage("images/arrows/prev-over.gif");
next_dis = newImage("images/arrows/next-dis.gif");
prev_dis = newImage("images/arrows/prev-dis.gif");
next_img = newImage("images/arrows/next.gif");
prev_img = newImage("images/arrows/prev.gif");

idx = 0;

function flipImg(inc) {
	var tmp = idx;
	idx = Math.min((sketch.length - 1), Math.max(0, (idx + inc) ));
	if (idx != tmp) {
		changeImages('sketch',sketch[idx]);
	}
	switch (idx) {
		case 0:
			changeImages('prev','images/arrows/prev-dis.gif');
			break;
		case (sketch.length - 1):
			changeImages('next','images/arrows/next-dis.gif');
			break;
		default:
			changeImages('next','images/arrows/next.gif');
			changeImages('prev','images/arrows/prev.gif');
	}
}

function rollOvr(name) {
	if (name == "next") {
		if (idx < (sketch.length - 1)) {
			changeImages('next','images/arrows/next-over.gif');
		}	
	} else {
		if (idx > 0) {
			changeImages('prev','images/arrows/prev-over.gif');
		}
	}
}

function rollOut(name) {
	if (name == "next") {
		if (idx < (sketch.length - 1)) {
			changeImages('next','images/arrows/next.gif');
		} else {
			changeImages('next','images/arrows/next-dis.gif');
		}
	} else {
		if (idx > 0) {
			changeImages('prev','images/arrows/prev.gif');
		} else {
			changeImages('prev','images/arrows/prev-dis.gif');
		}
	}
}